Free if you purchsed Blur Keyboard Pack.

Flat Keyboard Pack is a new keyboards design keyboard with blur background or solid background.

In Flat Keyboard Pack has over 20 keyboards with blur background and solid background (have a option to change it). BB = Blur Background.

Flat Keyboard hide only letters buttons, Blur Keyboard Pack hide only shift,delete etc buttons, Air Keyboard Pack hide all buttons.

Notes: In iOS 7.0 - 7.0.6 it's work perfect but for iOS 7.1 - 7.1.2, It's work but the blur of keys is less from iOS 7.0 (The screenshoot is from iOS 7.1.2). In iOS 7.0 - 7.0.6 I think the keyboards work with black and white keyboards.

For iOS 6 users the keyboards works but I think without blur I think is transparent I'm not tested it.

If you want the white keyboard for all apps to apply Blur Keyboard Pack for all wide-system download VintageKeys by Ryan Petrich.

Need ColorKeyboard from Cydia.